Learn Hardcore Chinese: Jīntiān lǎobǎn zài huìyìshì kāihuì kāi de hěn wǎn. - Today the boss had a meeting in the meeting room and worked until very late.

今 by itself means “the present; this”, and 天 means “day; sky”, but in modern everyday Chinese you almost always use 今天 as a fixed word.
Using 今 alone to mean “today” is rare and sounds archaic or literary, e.g. in set phrases like 今生 (this life), 今年 (this year).

The spaces in your example are just for teaching (to show characters and pinyin). In real Chinese writing, there would be no spaces and 今天 clearly functions as one unit.

2. Why is there no “the” or “my” before 老板? How do I know if it’s the boss, my boss, etc.?

Chinese usually doesn’t use articles like “the” or “a/an”, and often doesn’t say “my” when it’s obvious from context.

老板 (lǎobǎn) literally means “boss; shop owner; manager”.
In many real situations, if you say 老板, people will naturally interpret it as “my boss” (your own boss at work) unless the context suggests otherwise.

If you really want to make it explicit, you can say:

我的老板 – my boss
那个老板 – that boss / that shop owner
公司老板 – the company’s boss

But in a sentence like 今天老板在会议室开会开得很晚, just 老板 is completely natural and is usually understood as the relevant boss in the context, often “my boss” in English.

3. What exactly is 在 doing here? Is it “to be at” or just a preposition for location?

In 老板在会议室开会…, 在 (zài) marks location and works a bit like “at / in”:

Pattern: Subject + 在 + Place + Verb (do something)
- 老板在会议室开会 – The boss is/was having a meeting in the conference room.

So here 在 is:

Not just “to be located at” like a full verb in English.
Functioning like a preposition, introducing the place where the action (开会) happens.

This is a very common pattern:

他在学校工作。 – He works at school.
他们在咖啡馆聊天。 – They’re chatting in the café.

4. Why do we say 开会 instead of using a noun like “a meeting” (e.g. 有一个会议)?

In Chinese, 开会 (kāihuì) is a verb-object phrase that means “to hold / have a meeting”.

开 – to open; to run; to hold (a meeting, a class, etc.)
会 – meeting

So 开会 literally is “hold a meeting” and is the normal way to say “to have a meeting”.

You can say something like:

有一个会议 – there is a meeting / to have a meeting (more formal/descriptive)
开了一个会 – held a meeting

But in everyday speech, 开会 as a verb is by far the most common:

我们明天上午开会。 – We’re having a meeting tomorrow morning.
他们每天都要开会。 – They have to have a meeting every day.

In your sentence, 在会议室开会 is the natural way to say “have a meeting in the conference room”.

5. Why is 开 repeated in 开会开得很晚? Can’t I just say 开会得很晚?

The repetition is part of a very common grammar pattern: verb–object + verb + 得 + complement.

Here:

Verb–object: 开会 – have a meeting
Verb (repeated): 开 – hold (the meeting)
得 – links verb and complement
Complement: 很晚 – (until) very late

Pattern:
开会　开　得　很晚
[V‑O] [V] 得 [complement]

You cannot say ✗ 开会得很晚. The second 开 is required to connect to 得.

Other examples of the same pattern:

吃饭吃得很快。 – (He) eats very fast.
跑步跑得很累。 – (He) gets very tired from running.
说话说得很清楚。 – (He) speaks very clearly.

So 开会开得很晚 literally means “have a meeting, hold (it) so that it is very late” → “the meeting went on very late.”

6. What is 得 doing here? How is it different from 的 and 地?

得 (de) in 开得很晚 is a structural particle that links a verb to a complement describing the result, degree, or manner of the action.

Structure: Verb + 得 + complement
- 开得很晚 – (the meeting) is held very late
- 说得很好 – speak very well
- 跑得很快 – run very fast

It’s important not to confuse 得 with 的 and 地:

的: links a modifier to a noun
- 我的书 – my book
- 漂亮的衣服 – pretty clothes
地: links an adverbial modifier to a verb
- 高兴地说 – to speak happily
得: links a verb/adjective to a complement
- 说得很快 – speak very fast
- 累得不想动 – so tired that (I) don’t want to move

In your sentence, 开得很晚 = “(was) held very late,” describing how the meeting went.

7. Why do we need 很 before 晚? Can I just say 开得晚?

很 (hěn) is an adverb of degree meaning “very,” but in many sentences with a simple adjective, it can also act as a kind of “default” linker between the subject/verb and the adjective.

In 开得很晚:

很晚 literally: “very late”
Functionally: it can be just “late” or “quite late” in natural English, depending on context.

You can say 开得晚, and it’s grammatical. Differences:

开得很晚 – sounds more natural and fluent in everyday speech, and often feels a bit stronger / more vivid.
开得晚 – also OK, sometimes feels more neutral or slightly clipped.

With stative adjectives (e.g. 大, 小, 好, 高, 慢), native speakers very often insert 很 in these complement structures:

说得很慢 – speak slowly
写得很清楚 – write clearly

So 开得很晚 is the most idiomatic version.

8. Is 晚 here an adjective or an adverb? How is it different from 晚上?

In 开得很晚, 晚 (wǎn) is an adjective meaning “late” (opposite of early 早), and with 得 + 很晚 it functions like “late/very late” describing the degree/result of the action.

Literally: “(the meeting) was held to the point of being (very) late.”

It is not the same as:

晚上 (wǎnshang) – “evening / night (time)”

So:

开得很晚 – the meeting went on late (in terms of when it ended)
开到晚上十点 – (it) went until 10 p.m.
昨天晚上开会 – had a meeting last night

晚 here expresses lateness relative to expectation, not the part of the day.

9. Could 今天 go in another place, like 老板今天在会议室开会开得很晚? Is that still correct?

Yes, 今天 (time word) is quite flexible in position. Common positions include:

[Time] + Subject + …
- 今天老板在会议室开会开得很晚。
Subject + [Time] + …
- 老板今天在会议室开会开得很晚。

Both are grammatical and natural. The differences are subtle:

今天老板… – Slightly more focus on “as for today…”
老板今天… – Slightly more focus on “as for the boss today…”

In everyday conversation, 老板今天在会议室开会开得很晚 might even sound a bit more common, but both sentences are fine.

10. There’s no 了 in this sentence. How do I know it’s about the past? Would adding 了 change the meaning?

Chinese does not mark tense the way English does. Instead, it relies heavily on time words (like 今天) and context.

In 今天老板在会议室开会开得很晚。

今天 tells you this happened today.
Without extra context, it could describe a past event (e.g. said later in the day), or a habit (e.g. “These days, the boss has meetings that go late today” in a schedule context).

You can add 了 in various places, but each option has a nuance:

今天老板在会议室开会开得很晚了。
Often sounds like you’re commenting on a change or on the situation as it stands now (e.g. “It’s already very late that he’s still in a meeting”).
今天老板在会议室开了很晚的会。
Focus shifts to “(he) held a very late meeting (a meeting that was late)”; structure is different.

The original sentence without 了 is perfectly natural to describe something that happened earlier today, assuming the time word and context are clear.